The convergence of telecom and datacom technologies, as well as the blurring distinction between the system side and the cabling system of networks is driving a continuous evolution of structured cabling. User expectations and dependence on local area network (LAN) performance is creating an expectation beyond operational speed and reliability to further include device tracking and system management. Currently, limited progress has been made in such areas due to the impact of proposed improvements upon operational speed. As hubs and switches deal in logical addresses and network maps, asset location and connection management is best addressed through the cabling system. Development of advancements must address several evolving system features and requirements such as the detection of connected devices, including the addition, removal and/or movement of such devices accessing the system and the provision of power to connected devices.
The movement of devices accessing the system is one of several considerations during improvement developments. As described in U.S. Pat. No. 6,350,148, issued Feb. 26, 2002, to Batolutti et al., the subject matter of which is incorporated herein by reference, many businesses have dedicated telecommunication systems that enable computers, telephones, facsimile machines and the like to communicate with each other through a private network, and communicate with remote locations via a telecommunications service provider. In most buildings, the dedicated telecommunications system is hard wired using telecommunication cables that are coupled to individual service ports throughout the building. The wires from the dedicated service ports typically extend throughout the building and terminate at a patching system that is used to interconnect the various telecommunication lines. The patching system is usually located within a telecommunications closet and is most often positioned on a mounting frame that includes a number of racks or patch panels to which each telecommunication line is terminated. The patch panels include a number of port assemblies, such as RJ-45 telecommunication connector ports, and each telecommunication line is terminated to the patch panel in an organized manner.
One example of device movement considerations as disclosed in the Batolutti patent includes assigning one or more employees their own computer network access number exchange so that the employee can interface with a company main frame computer or computer network. As employees or equipment are moved, patch cords in a typical telecommunications closet are rearranged and new positions are manually documented using either paper or computer based logs. However, technicians often neglect to update the arrangement log each time a change is made. To correct this, manual tracing of the patch cord must be performed which can be both time consuming and prone to further errors.
Detecting connected devices is another consideration during improvement development which is commonly required for security purposes in many applications. Details of several examples of such detection issues are disclosed in U.S. Pat. No. 5,406,260, issued Apr. 11, 1995, to Cummings et al., the subject matter of which is incorporated herein by reference. A number of device detection methods have been developed for guarding against the unauthorized removal of electronic equipment, including methods that require the actual physical attachment of a security cord to each piece of protected equipment or the attachment of non-removal tags to the equipment. However, these methods require rather expensive sensing devices and are not very practical in all cases. In the device detection method disclosed in the Cummings patent, an isolation power supply is used to provide a low current DC power signal to each communication link and thereafter, monitor a circuit loop created through a DC resistive termination between the communication link and a remote device. Any interruption between the communication link and the remote device, such as the removal of the device from the communication link, disrupts the circuit loop and triggers an alarm.
Additional methods of circuit loop device detection also include the sensing of a current loop that is physically coupled to the protected equipment. One such method is disclosed in U.S. Pat. No. 4,654,640, issued Mar. 31, 1987, to Carll et al., the subject matter of which is incorporated herein by reference. The Carll patent discloses a theft alarm system for use with a digital signal PBX telephone system which includes a number of electronic tethers connected to individual pieces of protected equipment, each tether including a pair of conductors which are connected to form a closed current loop via a series resistor and conductive foil adhesively bonded to the equipment. Once assembled, the resulting circuit loop can be used for device removal detection, however, the conductive foil which is bonded to the equipment may be carefully removed without any detection.
The Batolutti patent also referenced above, discloses yet another method of detection for patch panel connectors themselves. A patch panel on which multiple mechanical sensors are mounted, serves to detect the presence or absence of a patch cord connector in a connector port on the panel and a computer controller connected to the multiple sensors may then be used to monitor changes in patch panel connections, such as when a connector is removed from a connector port. The detection, however, is limited to the mere absence or presence of a connector in a connector port.
Providing power to connected devices is yet another consideration during improvement development which can often include aspects of device detection as described above. Power applications, such as those found in power over ethernet technologies, allows IP telephones, wireless LAN Access Points and other appliances to receive power while also receiving data over existing LAN cabling without a need to modify ethernet infrastructure. Such technologies are described in IEEE802.3af, also known as Power Over Ethernet, which outlines the designs of Ethernet power-sourcing equipment and powered terminals.
Various methods for providing power to remote devices are also disclosed in U.S. Pat. No. 6,218,930, issued Apr. 17, 2001, to Katzenberg et al., the subject matter of which is incorporated herein by reference. In one example of a power application technology, an initial detection step is used prior to a power application step. Prior to applying external power to a device, automatic detection of connected equipment is accomplished by delivering a low level current to the network interface and measuring a voltage drop in the return path. The measurement can have three states, including no voltage drop, a fixed level voltage drop or a varying level voltage drop. As disclosed in the Katzenberg patent, if no voltage drop is detected, then the remote equipment does not contain a DC resistive termination and this equipment is identified as unable to support remote power feed. If a fixed voltage level is detected, the remote equipment contains a DC resistive termination, such as a “bob smith” termination and this equipment is also identified as being unable to support remote power feed. If a varying voltage level is detected, this detection indicates the presence of a DC-DC switching supply in the remote equipment and this equipment is identified as being able to support remote power feed which is then provided.
The attempts to address device movement and detection, as well as attempts to address providing power to connected devices, typically fail to consider the communication performance degradation that such solutions can create. Where attempts to correct performance degradation have been made, the solutions have typically been limited to the relocation and manipulation of signal traces. Examples of such solutions are disclosed in U.S. Pat. No. 5,797,764, issued Aug. 25, 1998, to Coulombe et al., and in U.S. Pat. No. 5,673,009, issued Sep. 30, 1997, to Klas et al., the subject matter of each being incorporated herein by reference. The Coulombe patent discloses a printed circuit board electrically coupling a connector block and jack assembly within a patch panel. Each signal trace on the board is provided a compensation trace aligned either above or below the respective signal trace for an electromagnetic connection between traces sufficient to reduce crosstalk. Trace manipulation is also disclosed in the Klas patent, which discusses a printed circuit board on which crosstalk is eliminated through the relocation of adjacent traces. Equal and opposite signal source traces are placed adjacent to one another such that cumulative crosstalk is eliminated. Unfortunately, trace manipulation is not sufficient in every case to provide category 3, 5, 5e, 6 and/or higher and equivalent performance levels.
Still further examples of such solutions are disclosed in U.S. Pat. No. 6,443,777, issued Sep. 3, 2002, to McCurdy et al., and in U.S. Pat. No. 6,464,541, issued Oct. 15, 2002, to Hashim et al., the subject matter of each being incorporated herein by reference. The McCurdy patent discloses an inductive and capacitive crosstalk compensation technique incorporated into a communication connector (i.e. modular jack) which includes the relocation of contact wires and the addition of a printed wiring board for capacitive coupling. The contact wires are separated by a distance set to obtain an adequate level of inductive compensation coupling, and a capacitive coupling is provided by one or more printed circuit boards located in the plug body as the contact wires are displaced. The use of such printed wiring boards is also discussed in the Hashim patent, which discloses a two stage crosstalk compensation technique. In a first stage, a printed wiring board is provided for capacitive coupling as the contact wires are displaced, and in a second stage, a printed wiring board is provided having a number of inductive loops and carefully positioned comb traces. Although both the McCurdy and Hashim patents address crosstalk reductions at the connector position, each fails to address the performance degradation beyond the connector, including performance degradation that can be created due to additional active circuitry elements involved in providing advanced features.
Accordingly, a need exists for an asset aware patch panel that can include advanced features for asset management and security, and can also provide compensation for active electronics used in achieving these and other advanced features.